1. Field of the Invention
This invention relates to carburettors for internal combustion engines, more particularly to carburettors which are regulated as a function of the composition of the exhaust gases.
2. Description of the Prior Art
It is a known practice, in particular from French Patent Application No. 74.30009 filed on Sept. 4, 1974, now French Patent No. 2,284,004, and French Patent Application No. 72.46845 of Dec. 29, 1972, now French Patent No. 2,174,501 constant vacuum carburettor provided with means of regulation as a function of the composition of the exhaust gases. According to Patent Application No. 74.30009 in particular, the partial vacuum transmitted to the movable element for the control of the needle and for closing the carburettor body is the partial vacuum prevailing upstream of the butterfly or other throttle valve modulated by an electromagnetic valve controlled by a probe located in the exhaust pipe and supplying a current variable as a function of the exhaust gases.
The present invention relates to improvements in devices of this type.